I couldn't find some SS hose clamps to secure the SS braid inside the mash tun. I found some zip ties in the electrical section, they are rated to 185*F, which should be high enough. You think the heating of the zip ties would be OK? Thanks

I can't see why it would hurt. I'm sure people are going to try and tell you that it will leach into your beer, but something that small shouldn't pose too much of a risk.
You may find yourself replacing them quite often though, as zip ties tend to get brittle after a little while, I would imagine temperature would compound that.
I was able to find SS hose clamps at Lowes, but you have to buy a pack of them.